diff options
Diffstat (limited to 'Documentation')
14 files changed, 390 insertions, 206 deletions
diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst index 9a60a5d60e38..7313d354f20e 100644 --- a/Documentation/bpf/btf.rst +++ b/Documentation/bpf/btf.rst @@ -148,16 +148,16 @@ The ``btf_type.size * 8`` must be equal to or greater than ``BTF_INT_BITS()`` for the type. The maximum value of ``BTF_INT_BITS()`` is 128. The ``BTF_INT_OFFSET()`` specifies the starting bit offset to calculate values -for this int. For example, a bitfield struct member has: * btf member bit -offset 100 from the start of the structure, * btf member pointing to an int -type, * the int type has ``BTF_INT_OFFSET() = 2`` and ``BTF_INT_BITS() = 4`` +for this int. For example, a bitfield struct member has: + * btf member bit offset 100 from the start of the structure, + * btf member pointing to an int type, + * the int type has ``BTF_INT_OFFSET() = 2`` and ``BTF_INT_BITS() = 4`` Then in the struct memory layout, this member will occupy ``4`` bits starting from bits ``100 + 2 = 102``. Alternatively, the bitfield struct member can be the following to access the same bits as the above: - * btf member bit offset 102, * btf member pointing to an int type, * the int type has ``BTF_INT_OFFSET() = 0`` and ``BTF_INT_BITS() = 4`` diff --git a/Documentation/devicetree/bindings/hwmon/adc128d818.txt b/Documentation/devicetree/bindings/hwmon/adc128d818.txt index 08bab0e94d25..d0ae46d7bac3 100644 --- a/Documentation/devicetree/bindings/hwmon/adc128d818.txt +++ b/Documentation/devicetree/bindings/hwmon/adc128d818.txt @@ -26,7 +26,7 @@ Required node properties: Optional node properties: - - ti,mode: Operation mode (see above). + - ti,mode: Operation mode (u8) (see above). Example (operation mode 2): @@ -34,5 +34,5 @@ Example (operation mode 2): adc128d818@1d { compatible = "ti,adc128d818"; reg = <0x1d>; - ti,mode = <2>; + ti,mode = /bits/ 8 <2>; }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-xscale.txt b/Documentation/devicetree/bindings/i2c/i2c-iop3xx.txt index dcc8390e0d24..dcc8390e0d24 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-xscale.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-iop3xx.txt diff --git a/Documentation/devicetree/bindings/i2c/i2c-mtk.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt index ee4c32454198..ee4c32454198 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mtk.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt diff --git a/Documentation/devicetree/bindings/i2c/i2c-st-ddci2c.txt b/Documentation/devicetree/bindings/i2c/i2c-stu300.txt index bd81a482634f..bd81a482634f 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-st-ddci2c.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-stu300.txt diff --git a/Documentation/devicetree/bindings/i2c/i2c-sunxi-p2wi.txt b/Documentation/devicetree/bindings/i2c/i2c-sun6i-p2wi.txt index 49df0053347a..49df0053347a 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-sunxi-p2wi.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-sun6i-p2wi.txt diff --git a/Documentation/devicetree/bindings/i2c/i2c-vt8500.txt b/Documentation/devicetree/bindings/i2c/i2c-wmt.txt index 94a425eaa6c7..94a425eaa6c7 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-vt8500.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-wmt.txt diff --git a/Documentation/devicetree/bindings/serial/mtk-uart.txt b/Documentation/devicetree/bindings/serial/mtk-uart.txt index 742cb470595b..bcfb13194f16 100644 --- a/Documentation/devicetree/bindings/serial/mtk-uart.txt +++ b/Documentation/devicetree/bindings/serial/mtk-uart.txt @@ -16,6 +16,7 @@ Required properties: * "mediatek,mt8127-uart" for MT8127 compatible UARTS * "mediatek,mt8135-uart" for MT8135 compatible UARTS * "mediatek,mt8173-uart" for MT8173 compatible UARTS + * "mediatek,mt8183-uart", "mediatek,mt6577-uart" for MT8183 compatible UARTS * "mediatek,mt6577-uart" for MT6577 and all of the above - reg: The base address of the UART register bank. diff --git a/Documentation/filesystems/mount_api.txt b/Documentation/filesystems/mount_api.txt index 944d1965e917..00ff0cfccfa7 100644 --- a/Documentation/filesystems/mount_api.txt +++ b/Documentation/filesystems/mount_api.txt @@ -12,11 +12,13 @@ CONTENTS (4) Filesystem context security. - (5) VFS filesystem context operations. + (5) VFS filesystem context API. - (6) Parameter description. + (6) Superblock creation helpers. - (7) Parameter helper functions. + (7) Parameter description. + + (8) Parameter helper functions. ======== @@ -41,12 +43,15 @@ The creation of new mounts is now to be done in a multistep process: (7) Destroy the context. -To support this, the file_system_type struct gains a new field: +To support this, the file_system_type struct gains two new fields: int (*init_fs_context)(struct fs_context *fc); + const struct fs_parameter_description *parameters; -which is invoked to set up the filesystem-specific parts of a filesystem -context, including the additional space. +The first is invoked to set up the filesystem-specific parts of a filesystem +context, including the additional space, and the second points to the +parameter description for validation at registration time and querying by a +future system call. Note that security initialisation is done *after* the filesystem is called so that the namespaces may be adjusted first. @@ -73,9 +78,9 @@ context. This is represented by the fs_context structure: void *s_fs_info; unsigned int sb_flags; unsigned int sb_flags_mask; + unsigned int s_iflags; + unsigned int lsm_flags; enum fs_context_purpose purpose:8; - bool sloppy:1; - bool silent:1; ... }; @@ -141,6 +146,10 @@ The fs_context fields are as follows: Which bits SB_* flags are to be set/cleared in super_block::s_flags. + (*) unsigned int s_iflags + + These will be bitwise-OR'd with s->s_iflags when a superblock is created. + (*) enum fs_context_purpose This indicates the purpose for which the context is intended. The @@ -150,17 +159,6 @@ The fs_context fields are as follows: FS_CONTEXT_FOR_SUBMOUNT -- New automatic submount of extant mount FS_CONTEXT_FOR_RECONFIGURE -- Change an existing mount - (*) bool sloppy - (*) bool silent - - These are set if the sloppy or silent mount options are given. - - [NOTE] sloppy is probably unnecessary when userspace passes over one - option at a time since the error can just be ignored if userspace deems it - to be unimportant. - - [NOTE] silent is probably redundant with sb_flags & SB_SILENT. - The mount context is created by calling vfs_new_fs_context() or vfs_dup_fs_context() and is destroyed with put_fs_context(). Note that the structure is not refcounted. @@ -342,28 +340,47 @@ number of operations used by the new mount code for this purpose: It should return 0 on success or a negative error code on failure. -================================= -VFS FILESYSTEM CONTEXT OPERATIONS -================================= +========================== +VFS FILESYSTEM CONTEXT API +========================== -There are four operations for creating a filesystem context and -one for destroying a context: +There are four operations for creating a filesystem context and one for +destroying a context: - (*) struct fs_context *vfs_new_fs_context(struct file_system_type *fs_type, - struct dentry *reference, - unsigned int sb_flags, - unsigned int sb_flags_mask, - enum fs_context_purpose purpose); + (*) struct fs_context *fs_context_for_mount( + struct file_system_type *fs_type, + unsigned int sb_flags); - Create a filesystem context for a given filesystem type and purpose. This - allocates the filesystem context, sets the superblock flags, initialises - the security and calls fs_type->init_fs_context() to initialise the - filesystem private data. + Allocate a filesystem context for the purpose of setting up a new mount, + whether that be with a new superblock or sharing an existing one. This + sets the superblock flags, initialises the security and calls + fs_type->init_fs_context() to initialise the filesystem private data. - reference can be NULL or it may indicate the root dentry of a superblock - that is going to be reconfigured (FS_CONTEXT_FOR_RECONFIGURE) or - the automount point that triggered a submount (FS_CONTEXT_FOR_SUBMOUNT). - This is provided as a source of namespace information. + fs_type specifies the filesystem type that will manage the context and + sb_flags presets the superblock flags stored therein. + + (*) struct fs_context *fs_context_for_reconfigure( + struct dentry *dentry, + unsigned int sb_flags, + unsigned int sb_flags_mask); + + Allocate a filesystem context for the purpose of reconfiguring an + existing superblock. dentry provides a reference to the superblock to be + configured. sb_flags and sb_flags_mask indicate which superblock flags + need changing and to what. + + (*) struct fs_context *fs_context_for_submount( + struct file_system_type *fs_type, + struct dentry *reference); + + Allocate a filesystem context for the purpose of creating a new mount for + an automount point or other derived superblock. fs_type specifies the + filesystem type that will manage the context and the reference dentry + supplies the parameters. Namespaces are propagated from the reference + dentry's superblock also. + + Note that it's not a requirement that the reference dentry be of the same + filesystem type as fs_type. (*) struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc); @@ -390,20 +407,6 @@ context pointer or a negative error code. For the remaining operations, if an error occurs, a negative error code will be returned. - (*) int vfs_get_tree(struct fs_context *fc); - - Get or create the mountable root and superblock, using the parameters in - the filesystem context to select/configure the superblock. This invokes - the ->validate() op and then the ->get_tree() op. - - [NOTE] ->validate() could perhaps be rolled into ->get_tree() and - ->reconfigure(). - - (*) struct vfsmount *vfs_create_mount(struct fs_context *fc); - - Create a mount given the parameters in the specified filesystem context. - Note that this does not attach the mount to anything. - (*) int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param); @@ -432,17 +435,80 @@ returned. clear the pointer, but then becomes responsible for disposing of the object. - (*) int vfs_parse_fs_string(struct fs_context *fc, char *key, + (*) int vfs_parse_fs_string(struct fs_context *fc, const char *key, const char *value, size_t v_size); - A wrapper around vfs_parse_fs_param() that just passes a constant string. + A wrapper around vfs_parse_fs_param() that copies the value string it is + passed. (*) int generic_parse_monolithic(struct fs_context *fc, void *data); Parse a sys_mount() data page, assuming the form to be a text list consisting of key[=val] options separated by commas. Each item in the list is passed to vfs_mount_option(). This is the default when the - ->parse_monolithic() operation is NULL. + ->parse_monolithic() method is NULL. + + (*) int vfs_get_tree(struct fs_context *fc); + + Get or create the mountable root and superblock, using the parameters in + the filesystem context to select/configure the superblock. This invokes + the ->get_tree() method. + + (*) struct vfsmount *vfs_create_mount(struct fs_context *fc); + + Create a mount given the parameters in the specified filesystem context. + Note that this does not attach the mount to anything. + + +=========================== +SUPERBLOCK CREATION HELPERS +=========================== + +A number of VFS helpers are available for use by filesystems for the creation +or looking up of superblocks. + + (*) struct super_block * + sget_fc(struct fs_context *fc, + int (*test)(struct super_block *sb, struct fs_context *fc), + int (*set)(struct super_block *sb, struct fs_context *fc)); + + This is the core routine. If test is non-NULL, it searches for an + existing superblock matching the criteria held in the fs_context, using + the test function to match them. If no match is found, a new superblock + is created and the set function is called to set it up. + + Prior to the set function being called, fc->s_fs_info will be transferred + to sb->s_fs_info - and fc->s_fs_info will be cleared if set returns + success (ie. 0). + +The following helpers all wrap sget_fc(): + + (*) int vfs_get_super(struct fs_context *fc, + enum vfs_get_super_keying keying, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc)) + + This creates/looks up a deviceless superblock. The keying indicates how + many superblocks of this type may exist and in what manner they may be + shared: + + (1) vfs_get_single_super + + Only one such superblock may exist in the system. Any further + attempt to get a new superblock gets this one (and any parameter + differences are ignored). + + (2) vfs_get_keyed_super + + Multiple superblocks of this type may exist and they're keyed on + their s_fs_info pointer (for example this may refer to a + namespace). + + (3) vfs_get_independent_super + + Multiple independent superblocks of this type may exist. This + function never matches an existing one and always creates a new + one. ===================== @@ -454,35 +520,22 @@ There's a core description struct that links everything together: struct fs_parameter_description { const char name[16]; - u8 nr_params; - u8 nr_alt_keys; - u8 nr_enums; - bool ignore_unknown; - bool no_source; - const char *const *keys; - const struct constant_table *alt_keys; const struct fs_parameter_spec *specs; const struct fs_parameter_enum *enums; }; For example: - enum afs_param { + enum { Opt_autocell, Opt_bar, Opt_dyn, Opt_foo, Opt_source, - nr__afs_params }; static const struct fs_parameter_description afs_fs_parameters = { .name = "kAFS", - .nr_params = nr__afs_params, - .nr_alt_keys = ARRAY_SIZE(afs_param_alt_keys), - .nr_enums = ARRAY_SIZE(afs_param_enums), - .keys = afs_param_keys, - .alt_keys = afs_param_alt_keys, .specs = afs_param_specs, .enums = afs_param_enums, }; @@ -494,28 +547,24 @@ The members are as follows: The name to be used in error messages generated by the parse helper functions. - (2) u8 nr_params; - - The number of discrete parameter identifiers. This indicates the number - of elements in the ->types[] array and also limits the values that may be - used in the values that the ->keys[] array maps to. - - It is expected that, for example, two parameters that are related, say - "acl" and "noacl" with have the same ID, but will be flagged to indicate - that one is the inverse of the other. The value can then be picked out - from the parse result. + (2) const struct fs_parameter_specification *specs; - (3) const struct fs_parameter_specification *specs; + Table of parameter specifications, terminated with a null entry, where the + entries are of type: - Table of parameter specifications, where the entries are of type: - - struct fs_parameter_type { - enum fs_parameter_spec type:8; - u8 flags; + struct fs_parameter_spec { + const char *name; + u8 opt; + enum fs_parameter_type type:8; + unsigned short flags; }; - and the parameter identifier is the index to the array. 'type' indicates - the desired value type and must be one of: + The 'name' field is a string to match exactly to the parameter key (no + wildcards, patterns and no case-independence) and 'opt' is the value that + will be returned by the fs_parser() function in the case of a successful + match. + + The 'type' field indicates the desired value type and must be one of: TYPE NAME EXPECTED VALUE RESULT IN ======================= ======================= ===================== @@ -525,85 +574,65 @@ The members are as follows: fs_param_is_u32_octal 32-bit octal int result->uint_32 fs_param_is_u32_hex 32-bit hex int result->uint_32 fs_param_is_s32 32-bit signed int result->int_32 + fs_param_is_u64 64-bit unsigned int result->uint_64 fs_param_is_enum Enum value name result->uint_32 fs_param_is_string Arbitrary string param->string fs_param_is_blob Binary blob param->blob fs_param_is_blockdev Blockdev path * Needs lookup fs_param_is_path Path * Needs lookup - fs_param_is_fd File descriptor param->file - - And each parameter can be qualified with 'flags': - - fs_param_v_optional The value is optional - fs_param_neg_with_no If key name is prefixed with "no", it is false - fs_param_neg_with_empty If value is "", it is false - fs_param_deprecated The parameter is deprecated. - - For example: - - static const struct fs_parameter_spec afs_param_specs[nr__afs_params] = { - [Opt_autocell] = { fs_param_is flag }, - [Opt_bar] = { fs_param_is_enum }, - [Opt_dyn] = { fs_param_is flag }, - [Opt_foo] = { fs_param_is_bool, fs_param_neg_with_no }, - [Opt_source] = { fs_param_is_string }, - }; + fs_param_is_fd File descriptor result->int_32 Note that if the value is of fs_param_is_bool type, fs_parse() will try to match any string value against "0", "1", "no", "yes", "false", "true". - [!] NOTE that the table must be sorted according to primary key name so - that ->keys[] is also sorted. - - (4) const char *const *keys; - - Table of primary key names for the parameters. There must be one entry - per defined parameter. The table is optional if ->nr_params is 0. The - table is just an array of names e.g.: + Each parameter can also be qualified with 'flags': - static const char *const afs_param_keys[nr__afs_params] = { - [Opt_autocell] = "autocell", - [Opt_bar] = "bar", - [Opt_dyn] = "dyn", - [Opt_foo] = "foo", - [Opt_source] = "source", - }; - - [!] NOTE that the table must be sorted such that the table can be searched - with bsearch() using strcmp(). This means that the Opt_* values must - correspond to the entries in this table. - - (5) const struct constant_table *alt_keys; - u8 nr_alt_keys; - - Table of additional key names and their mappings to parameter ID plus the - number of elements in the table. This is optional. The table is just an - array of { name, integer } pairs, e.g.: + fs_param_v_optional The value is optional + fs_param_neg_with_no result->negated set if key is prefixed with "no" + fs_param_neg_with_empty result->negated set if value is "" + fs_param_deprecated The parameter is deprecated. - static const struct constant_table afs_param_keys[] = { - { "baz", Opt_bar }, - { "dynamic", Opt_dyn }, + These are wrapped with a number of convenience wrappers: + + MACRO SPECIFIES + ======================= =============================================== + fsparam_flag() fs_param_is_flag + fsparam_flag_no() fs_param_is_flag, fs_param_neg_with_no + fsparam_bool() fs_param_is_bool + fsparam_u32() fs_param_is_u32 + fsparam_u32oct() fs_param_is_u32_octal + fsparam_u32hex() fs_param_is_u32_hex + fsparam_s32() fs_param_is_s32 + fsparam_u64() fs_param_is_u64 + fsparam_enum() fs_param_is_enum + fsparam_string() fs_param_is_string + fsparam_blob() fs_param_is_blob + fsparam_bdev() fs_param_is_blockdev + fsparam_path() fs_param_is_path + fsparam_fd() fs_param_is_fd + + all of which take two arguments, name string and option number - for + example: + + static const struct fs_parameter_spec afs_param_specs[] = { + fsparam_flag ("autocell", Opt_autocell), + fsparam_flag ("dyn", Opt_dyn), + fsparam_string ("source", Opt_source), + fsparam_flag_no ("foo", Opt_foo), + {} }; - [!] NOTE that the table must be sorted such that strcmp() can be used with - bsearch() to search the entries. - - The parameter ID can also be fs_param_key_removed to indicate that a - deprecated parameter has been removed and that an error will be given. - This differs from fs_param_deprecated where the parameter may still have - an effect. - - Further, the behaviour of the parameter may differ when an alternate name - is used (for instance with NFS, "v3", "v4.2", etc. are alternate names). + An addition macro, __fsparam() is provided that takes an additional pair + of arguments to specify the type and the flags for anything that doesn't + match one of the above macros. (6) const struct fs_parameter_enum *enums; - u8 nr_enums; - Table of enum value names to integer mappings and the number of elements - stored therein. This is of type: + Table of enum value names to integer mappings, terminated with a null + entry. This is of type: struct fs_parameter_enum { - u8 param_id; + u8 opt; char name[14]; u8 value; }; @@ -621,11 +650,6 @@ The members are as follows: try to look the value up in the enum table and the result will be stored in the parse result. - (7) bool no_source; - - If this is set, fs_parse() will ignore any "source" parameter and not - pass it to the filesystem. - The parser should be pointed to by the parser pointer in the file_system_type struct as this will provide validation on registration (if CONFIG_VALIDATE_FS_PARSER=y) and will allow the description to be queried from @@ -650,9 +674,8 @@ process the parameters it is given. int value; }; - and it must be sorted such that it can be searched using bsearch() using - strcmp(). If a match is found, the corresponding value is returned. If a - match isn't found, the not_found value is returned instead. + If a match is found, the corresponding value is returned. If a match + isn't found, the not_found value is returned instead. (*) bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, @@ -665,36 +688,36 @@ process the parameters it is given. should just be set to lie inside the low-to-high range. If all is good, true is returned. If the table is invalid, errors are - logged to dmesg, the stack is dumped and false is returned. + logged to dmesg and false is returned. + + (*) bool fs_validate_description(const struct fs_parameter_description *desc); + + This performs some validation checks on a parameter description. It + returns true if the description is good and false if it is not. It will + log errors to dmesg if validation fails. (*) int fs_parse(struct fs_context *fc, - const struct fs_param_parser *parser, + const struct fs_parameter_description *desc, struct fs_parameter *param, - struct fs_param_parse_result *result); + struct fs_parse_result *result); This is the main interpreter of parameters. It uses the parameter - description (parser) to look up the name of the parameter to use and to - convert that to a parameter ID (stored in result->key). + description to look up a parameter by key name and to convert that to an + option number (which it returns). If successful, and if the parameter type indicates the result is a boolean, integer or enum type, the value is converted by this function and - the result stored in result->{boolean,int_32,uint_32}. + the result stored in result->{boolean,int_32,uint_32,uint_64}. If a match isn't initially made, the key is prefixed with "no" and no value is present then an attempt will be made to look up the key with the prefix removed. If this matches a parameter for which the type has flag - fs_param_neg_with_no set, then a match will be made and the value will be - set to false/0/NULL. - - If the parameter is successfully matched and, optionally, parsed - correctly, 1 is returned. If the parameter isn't matched and - parser->ignore_unknown is set, then 0 is returned. Otherwise -EINVAL is - returned. - - (*) bool fs_validate_description(const struct fs_parameter_description *desc); + fs_param_neg_with_no set, then a match will be made and result->negated + will be set to true. - This is validates the parameter description. It returns true if the - description is good and false if it is not. + If the parameter isn't matched, -ENOPARAM will be returned; if the + parameter is matched, but the value is erroneous, -EINVAL will be + returned; otherwise the parameter's option number will be returned. (*) int fs_lookup_param(struct fs_context *fc, struct fs_parameter *value, diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801 index d1ee484a787d..ee9984f35868 100644 --- a/Documentation/i2c/busses/i2c-i801 +++ b/Documentation/i2c/busses/i2c-i801 @@ -36,6 +36,7 @@ Supported adapters: * Intel Cannon Lake (PCH) * Intel Cedar Fork (PCH) * Intel Ice Lake (PCH) + * Intel Comet Lake (PCH) Datasheets: Publicly available at the Intel website On Intel Patsburg and later chipsets, both the normal host SMBus controller diff --git a/Documentation/networking/bpf_flow_dissector.rst b/Documentation/networking/bpf_flow_dissector.rst new file mode 100644 index 000000000000..b375ae2ec2c4 --- /dev/null +++ b/Documentation/networking/bpf_flow_dissector.rst @@ -0,0 +1,126 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================== +BPF Flow Dissector +================== + +Overview +======== + +Flow dissector is a routine that parses metadata out of the packets. It's +used in the various places in the networking subsystem (RFS, flow hash, etc). + +BPF flow dissector is an attempt to reimplement C-based flow dissector logic +in BPF to gain all the benefits of BPF verifier (namely, limits on the +number of instructions and tail calls). + +API +=== + +BPF flow dissector programs operate on an ``__sk_buff``. However, only the +limited set of fields is allowed: ``data``, ``data_end`` and ``flow_keys``. +``flow_keys`` is ``struct bpf_flow_keys`` and contains flow dissector input +and output arguments. + +The inputs are: + * ``nhoff`` - initial offset of the networking header + * ``thoff`` - initial offset of the transport header, initialized to nhoff + * ``n_proto`` - L3 protocol type, parsed out of L2 header + +Flow dissector BPF program should fill out the rest of the ``struct +bpf_flow_keys`` fields. Input arguments ``nhoff/thoff/n_proto`` should be +also adjusted accordingly. + +The return code of the BPF program is either BPF_OK to indicate successful +dissection, or BPF_DROP to indicate parsing error. + +__sk_buff->data +=============== + +In the VLAN-less case, this is what the initial state of the BPF flow +dissector looks like:: + + +------+------+------------+-----------+ + | DMAC | SMAC | ETHER_TYPE | L3_HEADER | + +------+------+------------+-----------+ + ^ + | + +-- flow dissector starts here + + +.. code:: c + + skb->data + flow_keys->nhoff point to the first byte of L3_HEADER + flow_keys->thoff = nhoff + flow_keys->n_proto = ETHER_TYPE + +In case of VLAN, flow dissector can be called with the two different states. + +Pre-VLAN parsing:: + + +------+------+------+-----+-----------+-----------+ + | DMAC | SMAC | TPID | TCI |ETHER_TYPE | L3_HEADER | + +------+------+------+-----+-----------+-----------+ + ^ + | + +-- flow dissector starts here + +.. code:: c + + skb->data + flow_keys->nhoff point the to first byte of TCI + flow_keys->thoff = nhoff + flow_keys->n_proto = TPID + +Please note that TPID can be 802.1AD and, hence, BPF program would +have to parse VLAN information twice for double tagged packets. + + +Post-VLAN parsing:: + + +------+------+------+-----+-----------+-----------+ + | DMAC | SMAC | TPID | TCI |ETHER_TYPE | L3_HEADER | + +------+------+------+-----+-----------+-----------+ + ^ + | + +-- flow dissector starts here + +.. code:: c + + skb->data + flow_keys->nhoff point the to first byte of L3_HEADER + flow_keys->thoff = nhoff + flow_keys->n_proto = ETHER_TYPE + +In this case VLAN information has been processed before the flow dissector +and BPF flow dissector is not required to handle it. + + +The takeaway here is as follows: BPF flow dissector program can be called with +the optional VLAN header and should gracefully handle both cases: when single +or double VLAN is present and when it is not present. The same program +can be called for both cases and would have to be written carefully to +handle both cases. + + +Reference Implementation +======================== + +See ``tools/testing/selftests/bpf/progs/bpf_flow.c`` for the reference +implementation and ``tools/testing/selftests/bpf/flow_dissector_load.[hc]`` +for the loader. bpftool can be used to load BPF flow dissector program as well. + +The reference implementation is organized as follows: + * ``jmp_table`` map that contains sub-programs for each supported L3 protocol + * ``_dissect`` routine - entry point; it does input ``n_proto`` parsing and + does ``bpf_tail_call`` to the appropriate L3 handler + +Since BPF at this point doesn't support looping (or any jumping back), +jmp_table is used instead to handle multiple levels of encapsulation (and +IPv6 options). + + +Current Limitations +=================== +BPF flow dissector doesn't support exporting all the metadata that in-kernel +C-based implementation can export. Notable example is single VLAN (802.1Q) +and double VLAN (802.1AD) tags. Please refer to the ``struct bpf_flow_keys`` +for a set of information that's currently can be exported from the BPF context. diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index 5449149be496..984e68f9e026 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -9,6 +9,7 @@ Contents: netdev-FAQ af_xdp batman-adv + bpf_flow_dissector can can_ucan_protocol device_drivers/freescale/dpaa2/index diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 7de9eee73fcd..67068c47c591 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -5,25 +5,32 @@ The Definitive KVM (Kernel-based Virtual Machine) API Documentation ---------------------- The kvm API is a set of ioctls that are issued to control various aspects -of a virtual machine. The ioctls belong to three classes +of a virtual machine. The ioctls belong to three classes: - System ioctls: These query and set global attributes which affect the whole kvm subsystem. In addition a system ioctl is used to create - virtual machines + virtual machines. - VM ioctls: These query and set attributes that affect an entire virtual machine, for example memory layout. In addition a VM ioctl is used to - create virtual cpus (vcpus). + create virtual cpus (vcpus) and devices. - Only run VM ioctls from the same process (address space) that was used - to create the VM. + VM ioctls must be issued from the same process (address space) that was + used to create the VM. - vcpu ioctls: These query and set attributes that control the operation of a single virtual cpu. - Only run vcpu ioctls from the same thread that was used to create the - vcpu. + vcpu ioctls should be issued from the same thread that was used to create + the vcpu, except for asynchronous vcpu ioctl that are marked as such in + the documentation. Otherwise, the first ioctl after switching threads + could see a performance impact. + - device ioctls: These query and set attributes that control the operation + of a single device. + + device ioctls must be issued from the same process (address space) that + was used to create the VM. 2. File descriptors ------------------- @@ -32,17 +39,34 @@ The kvm API is centered around file descriptors. An initial open("/dev/kvm") obtains a handle to the kvm subsystem; this handle can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this handle will create a VM file descriptor which can be used to issue VM -ioctls. A KVM_CREATE_VCPU ioctl on a VM fd will create a virtual cpu -and return a file descriptor pointing to it. Finally, ioctls on a vcpu -fd can be used to control the vcpu, including the important task of -actually running guest code. +ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will +create a virtual cpu or device and return a file descriptor pointing to +the new resource. Finally, ioctls on a vcpu or device fd can be used +to control the vcpu or device. For vcpus, this includes the important +task of actually running guest code. In general file descriptors can be migrated among processes by means of fork() and the SCM_RIGHTS facility of unix domain socket. These kinds of tricks are explicitly not supported by kvm. While they will not cause harm to the host, their actual behavior is not guaranteed by -the API. The only supported use is one virtual machine per process, -and one vcpu per thread. +the API. See "General description" for details on the ioctl usage +model that is supported by KVM. + +It is important to note that althought VM ioctls may only be issued from +the process that created the VM, a VM's lifecycle is associated with its +file descriptor, not its creator (process). In other words, the VM and +its resources, *including the associated address space*, are not freed +until the last reference to the VM's file descriptor has been released. +For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will +not be freed until both the parent (original) process and its child have +put their references to the VM's file descriptor. + +Because a VM's resources are not freed until the last reference to its +file descriptor is released, creating additional references to a VM via +via fork(), dup(), etc... without careful consideration is strongly +discouraged and may have unwanted side effects, e.g. memory allocated +by and on behalf of the VM's process may not be freed/unaccounted when +the VM is shut down. It is important to note that althought VM ioctls may only be issued from @@ -515,11 +539,15 @@ c) KVM_INTERRUPT_SET_LEVEL Note that any value for 'irq' other than the ones stated above is invalid and incurs unexpected behavior. +This is an asynchronous vcpu ioctl and can be invoked from any thread. + MIPS: Queues an external interrupt to be injected into the virtual CPU. A negative interrupt number dequeues the interrupt. +This is an asynchronous vcpu ioctl and can be invoked from any thread. + 4.17 KVM_DEBUG_GUEST @@ -1086,14 +1114,12 @@ struct kvm_userspace_memory_region { #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) #define KVM_MEM_READONLY (1UL << 1) -This ioctl allows the user to create or modify a guest physical memory -slot. When changing an existing slot, it may be moved in the guest -physical memory space, or its flags may be modified. It may not be -resized. Slots may not overlap in guest physical address space. -Bits 0-15 of "slot" specifies the slot id and this value should be -less than the maximum number of user memory slots supported per VM. -The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS, -if this capability is supported by the architecture. +This ioctl allows the user to create, modify or delete a guest physical +memory slot. Bits 0-15 of "slot" specify the slot id and this value +should be less than the maximum number of user memory slots supported per +VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS, +if this capability is supported by the architecture. Slots may not +overlap in guest physical address space. If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" specifies the address space which is being modified. They must be @@ -1102,6 +1128,10 @@ KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces are unrelated; the restriction on overlapping slots only applies within each address space. +Deleting a slot is done by passing zero for memory_size. When changing +an existing slot, it may be moved in the guest physical memory space, +or its flags may be modified, but it may not be resized. + Memory for the region is taken starting at the address denoted by the field userspace_addr, which must point at user addressable memory for the entire memory slot size. Any object may back this memory, including @@ -2493,7 +2523,7 @@ KVM_S390_MCHK (vm, vcpu) - machine check interrupt; cr 14 bits in parm, machine checks needing further payload are not supported by this ioctl) -Note that the vcpu ioctl is asynchronous to vcpu execution. +This is an asynchronous vcpu ioctl and can be invoked from any thread. 4.78 KVM_PPC_GET_HTAB_FD @@ -3042,8 +3072,7 @@ KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall KVM_S390_MCHK - machine check interrupt; parameters in .mchk - -Note that the vcpu ioctl is asynchronous to vcpu execution. +This is an asynchronous vcpu ioctl and can be invoked from any thread. 4.94 KVM_S390_GET_IRQ_STATE diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index f365102c80f5..2efe0efc516e 100644 --- a/Documentation/virtual/kvm/mmu.txt +++ b/Documentation/virtual/kvm/mmu.txt @@ -142,7 +142,7 @@ Shadow pages contain the following information: If clear, this page corresponds to a guest page table denoted by the gfn field. role.quadrant: - When role.cr4_pae=0, the guest uses 32-bit gptes while the host uses 64-bit + When role.gpte_is_8_bytes=0, the guest uses 32-bit gptes while the host uses 64-bit sptes. That means a guest page table contains more ptes than the host, so multiple shadow pages are needed to shadow one guest page. For first-level shadow pages, role.quadrant can be 0 or 1 and denotes the @@ -158,9 +158,9 @@ Shadow pages contain the following information: The page is invalid and should not be used. It is a root page that is currently pinned (by a cpu hardware register pointing to it); once it is unpinned it will be destroyed. - role.cr4_pae: - Contains the value of cr4.pae for which the page is valid (e.g. whether - 32-bit or 64-bit gptes are in use). + role.gpte_is_8_bytes: + Reflects the size of the guest PTE for which the page is valid, i.e. '1' + if 64-bit gptes are in use, '0' if 32-bit gptes are in use. role.nxe: Contains the value of efer.nxe for which the page is valid. role.cr0_wp: @@ -173,6 +173,9 @@ Shadow pages contain the following information: Contains the value of cr4.smap && !cr0.wp for which the page is valid (pages for which this is true are different from other pages; see the treatment of cr0.wp=0 below). + role.ept_sp: + This is a virtual flag to denote a shadowed nested EPT page. ept_sp + is true if "cr0_wp && smap_andnot_wp", an otherwise invalid combination. role.smm: Is 1 if the page is valid in system management mode. This field determines which of the kvm_memslots array was used to build this |